Improve JIT support for linux/ppc: Patch by Nicolas Geoffray!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34572 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 65 insertions, 0 deletions

diff --git a/lib/Target/PowerPC/PPCJITInfo.cpp b/lib/Target/PowerPC/PPCJITInfo.cpp
index 02554ff730..a8497fe1c8 100644
--- a/lib/Target/PowerPC/PPCJITInfo.cpp
+++ b/lib/Target/PowerPC/PPCJITInfo.cpp
@@ -134,6 +134,71 @@ asm(
     "mtlr r2\n"
     "bctr\n"
     );
+
+#elif defined(__PPC__) && !defined(__ppc64__)
+// Linux/PPC support
+
+// CompilationCallback stub - We can't use a C function with inline assembly in
+// it, because we the prolog/epilog inserted by GCC won't work for us.  Instead,
+// write our own wrapper, which does things our way, so we have complete control
+// over register saving and restoring.
+asm(
+    ".text\n"
+    ".align 2\n"
+    ".globl PPC32CompilationCallback\n"
+"PPC32CompilationCallback:\n"
+    // Make space for 8 ints r[3-10] and 13 doubles f[1-13] and the 
+    // FIXME: need to save v[0-19] for altivec?
+    // FIXME: could shrink frame
+    // Set up a proper stack frame
+    // FIXME Layout
+    //   PowerPC64 ABI linkage    -  24 bytes
+    //                 parameters -  32 bytes
+    //   13 double registers      - 104 bytes
+    //   8 int registers          -  32 bytes
+    "mflr 0\n"
+    "stw 0,  4(1)\n"
+    "stwu 1, -180(1)\n"
+    // Save all int arg registers
+    "stw 10, 176(1)\n"    "stw 9,  172(1)\n"
+    "stw 8,  168(1)\n"    "stw 7,  164(1)\n"
+    "stw 6,  160(1)\n"    "stw 5,  156(1)\n"
+    "stw 4,  152(1)\n"    "stw 3,  148(1)\n"
+    // Save all call-clobbered FP regs.
+    "stfd 10, 144(1)\n"
+    "stfd 9,  136(1)\n"   "stfd 8,  128(1)\n"
+    "stfd 7,  120(1)\n"   "stfd 6,  112(1)\n"
+    "stfd 5,  104(1)\n"   "stfd 4,   96(1)\n"
+    "stfd 3,   88(1)\n"   "stfd 2,   80(1)\n"
+    "stfd 1,   72(1)\n"
+    // Arguments to Compilation Callback:
+    // r3 - our lr (address of the call instruction in stub plus 4)
+    // r4 - stub's lr (address of instruction that called the stub plus 4)
+    // r5 - is64Bit - always 0.
+    "mr   3, 0\n"
+    "lwz  11, 180(1)\n" // stub's frame
+    "lwz  4, 4(11)\n" // stub's lr
+    "li   5, 0\n"       // 0 == 32 bit
+    "bl PPCCompilationCallbackC\n"
+    "mtctr 3\n"
+    // Restore all int arg registers
+    "lwz 10, 176(1)\n"    "lwz 9,  172(1)\n"
+    "lwz 8,  168(1)\n"    "lwz 7,  164(1)\n"
+    "lwz 6,  160(1)\n"    "lwz 5,  156(1)\n"
+    "lwz 4,  152(1)\n"    "lwz 3,  148(1)\n"
+    // Restore all FP arg registers
+    "lfd 10, 144(1)\n"
+    "lfd 9,  136(1)\n"    "lfd 8,  128(1)\n"
+    "lfd 7,  120(1)\n"    "lfd 6,  112(1)\n"
+    "lfd 5,  104(1)\n"    "lfd 4,   96(1)\n"
+    "lfd 3,   88(1)\n"    "lfd 2,   80(1)\n"
+    "lfd 1,   72(1)\n"
+    // Pop 3 frames off the stack and branch to target
+    "lwz  1, 184(1)\n"
+    "lwz  11, 4(1)\n"
+    "mtlr 11\n"
+    "bctr\n"
+    );
 #else
 void PPC32CompilationCallback() {
   assert(0 && "This is not a power pc, you can't execute this!");